Injection-molded window panel and related methods

ABSTRACT

A window panel adapted for installation relative to a structure. The panel includes a single piece of generally transparent injection-molded material configured to span one or more openings in the structure. The panel has panel attachment inserts for attaching the panel relative to the structure. The inserts are embedded in the material alongside at least one edge of the panel. The panel has a curvature that essentially continues a curvature of the structure surrounding the opening(s) when the panel is installed relative to the structure. This panel can be single-pane and can provide an essentially continuous window along an aircraft fuselage.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.10/958,078, filed Oct. 4, 2004, which is related to U.S. patentapplication Ser. No. 10/958,079, filed Oct. 4, 2004 and U.S. patentapplication Ser. No. 10/958,080, filed on Oct. 4, 2004 (now U.S. Pat.No. 7,503,531), the disclosures of which are incorporated herein byreference.

FIELD OF THE INVENTION

The present invention relates to window panels, and more particularly(but not exclusively) to a generally transparent window panel for use inaircraft, trains, boats, buses and other mobile or stationarystructures.

BACKGROUND OF THE INVENTION

Most private and commercial aircraft have side windows that appear assmall portholes along the sides of the aircraft. Each window typicallyincludes multiple panes of acrylic and/or glass, for example, a thickouter pane separated by an air gap from a thin inner pane. The two panesare mounted in a silicon seal to maintain the air gap separation betweenthe panes. These windows typically are mounted in a heavy supportstructure that limits the size and location of the windows.

SUMMARY OF THE INVENTION

The present invention, in one configuration, is directed to a windowpanel adapted for installation relative to a structure. The panelincludes a single piece of generally transparent injection-moldedmaterial configured to span one or more openings in the structure. Thepanel also includes a plurality of panel attachment inserts forattaching the panel relative to the structure. The inserts are embeddedin the material alongside at least one edge of the panel. The panel hasa curvature configured to essentially continue a curvature of thestructure surrounding the one or more openings when the panel isinstalled relative to the structure.

In another configuration, a window panel adapted for installationrelative to a structure includes a single piece of generally transparentinjection-molded material. The material has at least one edge configuredto abut a support member of the structure and at least one other edgeconfigured to abut an edge of another window panel of the structure. Thepanel has a curvature generally continuous with a surface curvature ofthe structure when the panel is installed relative to the structure.

In one implementation, the invention is directed to a method ofinstalling an injection-molded window panel relative to a structure. Oneor more edges of the panel are matched to one or more openings in thestructure such that a curvature of the structure is made essentiallycontinuous by a curvature of the panel over the one or more openings. Atleast one fastener is installed into at least one of a plurality ofpanel attachment inserts embedded in the panel alongside at least one ofthe edges of the panel to attach the panel relative to the structure.

In another implementation, the invention is directed to a method ofmaking a window panel for installation relative to a structure. Aplurality of attachment inserts are placed in a mold. A polymericmaterial is injected into the mold to embed the inserts in the materialalongside one or more edges of the material defined at least partly bythe mold. The injected material is removed from the mold. The injectingstep includes molding the material into a generally transparent panelhaving a shape configured to span one or more openings in the structurewhile generally continuing a curvature of the structure surrounding theone or more openings when the panel is installed relative to thestructure.

The features, functions, and advantages can be achieved independently invarious embodiments of the present inventions or may be combined in yetother embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is an exploded perspective view of a window panel relative to aportion of an aircraft fuselage in accordance with one configuration ofthe present invention;

FIG. 2 is a detail on an enlarged scale taken along line 2-2 in FIG. 1;

FIG. 3 is an interior perspective view of a portion of an aircraftfuselage cut away to show window panels in accordance with oneconfiguration of the present invention;

FIG. 4 is a detail on an enlarged scale taken along line 4-4 in FIG. 3;

FIG. 5 is a sectional view, taken along the plane of line 5-5 in FIG. 4,of two window panel ends mounted relative to an aircraft support memberin accordance with one configuration of the present invention;

FIG. 6 is a sectional view, taken along the plane of line 6-6 in FIG. 4,of a window panel upper end mounted relative to an aircraft longeron inaccordance with one configuration of the present invention;

FIG. 7 is a cross-sectional view of a closed-cavity mold in accordancewith one configuration of the present invention; and

FIG. 8 is a perspective view of a window panel in accordance with oneconfiguration of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiment(s) is merelyexemplary in nature and is in no way intended to limit the invention,its application, or uses. For purposes of clarity, the same referencenumbers may be used in the drawings to identify similar elements.Although various configurations of the present invention are describedherein with reference to aircraft, the invention is not so limited.Embodiments of the invention are contemplated in connection with othertypes of mobile platforms, for example, trains, buses, boats and othervehicles. Configurations also are contemplated in connection withstationary structures.

Referring now to FIG. 1, a structure, e.g., an aircraft fuselage inaccordance with one configuration of the present invention, is partiallyshown and indicated generally by reference number 12. An embodiment of awindow panel 20 is adapted for installation relative to the fuselage 12.The panel 20 includes a single piece of generally transparentinjection-molded material 28 that, when installed relative to thefuselage 12, spans one or more openings 32 in the fuselage 12. Threewindow panels 20 are shown in FIG. 1, each panel spanning four openings32. It should be understood, however, that in other configurations apanel 20 could span more than four or fewer than four openings 32. Thus,for example, a panel 20 could be configured to span a single opening 32.In the present exemplary configuration, the openings 32 are defined atleast partially by aircraft support members, e.g., hoop frames andlongerons of the fuselage 12 as further described below. It should benoted that openings could be defined in other or additional ways inother configurations and other structures.

A portion of the window panel 20 is shown in greater detail in FIG. 2.The window panel 20 has a curvature that follows one or more mold linesof the fuselage 12. In other words, the window panel 20 has a curvaturethat generally continues a surface curvature of the fuselage 12surrounding the opening(s) 32 when the panel 20 is installed relative tothe fuselage 12. Thus, as can be seen in FIG. 2, the window panel 20 hasa convex curvature that generally continues a convex curvature of thefuselage 12. In other implementations, however, a window panel couldinclude curved and/or flat portions that differ in curvature and/orflatness from a structure relative to which such panel is installed.

The panel 20 may be reversibly installed relative to an exterior side 40of the fuselage 12. A plurality of panel attachment inserts 44 areembedded in the panel 20 alongside one or more panel edges, e.g.,alongside one or both of two side edge(s) 48 (one of which is shown inFIG. 2), alongside an upper edge 60, and/or alongside a lower edge 80.The attachment inserts 44 may be used to attach the panel to thefuselage 12 as further described below. The attachment inserts 44 may befabricated of metal, for example, 17-4 PH stainless steel or othersuitable materials.

An upper end 52 of the panel 20 is attached via inserts 44 to an upperlongeron 56 of the aircraft. The upper edge 60 of the panel abuts anedge 64 of a skin 68 of the aircraft. A lower end 72 of the panel isattached via inserts 44 to a lower longeron 76. The lower edge 80 of thepanel abuts an edge 84 of the skin 68. In another configuration, one ormore ends of the panel 20 could be lap-spliced to the skin 68.

At least one side end 88 of the panel 20 may be attached relative to anaircraft support member 90 via inserts 44 and, for example, via a windowpanel splice fitting 92. In the present configuration the panel 20spans, but may not necessarily be attached to, one or more interveningsupport members 90, one of which is visible in FIG. 2 through the panel20. It can be easily appreciated that in other configurations, a windowpanel in accordance with principles of the present invention may have adifferent shape and/or curvature to span a different opening in adifferent structure. Although inserts 44 and window panel splicefittings 92 are used in the present configuration to attach the windowpanel 20 relative to one or more support members 90, configurations alsoare contemplated in which other or additional types of attachmentelements are used to install a window panel relative to a structure.

An interior perspective view of part of the fuselage 12 is shown in FIG.3. The fuselage 12 includes a plurality of vertically oriented hoopframe support members 90 and a plurality of horizontally orientedstringers 98. FIG. 4 is a detail of the fuselage 12 on an enlarged scaletaken along line 4-4 in FIG. 3.

FIG. 5 is a sectional view, taken along the plane of line 5-5 in FIG. 4,of two window panel side ends 88 mounted relative to a support member 90in accordance with one configuration of the present invention. In thepresent configuration, each attachment insert 44 has a tapered shape,thereby providing a distal end 104 that is wider than a proximal end 108of the insert. The proximal end 108 is positioned in the panel 20 toreceive a fastener 112 for attaching the panel 20 to the fuselage 12.

The two panel side ends 88 shown in FIG. 5 are mounted such that sideedges 48 of the panels 20 abut each other. A seal 120 is applied to thepanel side ends 88 over the attachment inserts 44, and a window panelsplice fitting 92 is placed over the seal. Alternatively, the seal 120could be applied to the window panel splice fitting 92, and the splicefitting 92 could be placed over the attachment inserts 44. The seal 120may be, for example, fabricated of neoprene or silicone rubber.Fasteners 112 are installed through the splice fitting 92 and seal 120and into the attachment inserts 44. In a preferred embodiment, afastener 112 is installed through the proximal end 108 of an attachmentinsert 44 without penetrating the distal end 104 of the attachmentinsert. The splice fitting 92 may be fastened to the support member 90using fasteners 124.

FIG. 6 is a sectional view of part of the fuselage 12, taken along theplane of line 6-6 in FIG. 4. The window panel upper end 52 is mountedrelative to the upper longeron 56 in accordance with one configurationof the present invention. The panel upper end 52 fits in a recess 204 ofthe longeron 56 such that an outer surface 208 of the panel end 52 isgenerally continuous with an outer surface 212 of the skin 40. Anattachment insert 44 embedded in the panel end 52 is aligned with aspine 216 of the longeron 56.

When the window panel upper end 52 is mounted relative to the longeron56, a seal 220 is applied between the longeron 56 and panel upper end52, and the upper end 52 is positioned in the recess 204. The seal 220may be, for example, fabricated of neoprene or silicone rubber. Afastener 224 is installed through the longeron spine 216 and seal 220and into the attachment insert 44. In a preferred embodiment, thefastener 224 is installed through the proximal end 108 of the attachmentinsert 44 without penetrating the distal end 104 of the attachmentinsert.

The window panel 20 may be fabricated using a polymeric material, forexample, aerospace grade polycarbonate or acrylic. Such materials mayinclude but are not limited to Lexan® 103-polycarbonate, available fromGeneral Electric Company of Fairfield, Conn., and/or Plexiglas®HFI-acrylic, available from Atofina Chemicals, Inc. of Philadelphia, Pa.Although a window panel 20 may be fabricated from polycarbonate and/oracrylic materials, chemically resistant versions of polyurethane may beused in other configurations.

A closed-cavity mold is indicated generally in FIG. 7 by referencenumber 300. The mold 300 includes inner surfaces 304 appropriate forproducing a window panel having a desirable shape and opticalcharacteristics. The polymeric material may be injection-molded in themold 300 under heat at about 530 F plus or minus about 20 F, and atpressure between about 1500 and 2000 psi.

In one implementation, before being injected into the mold 300, thepolymeric material is dried at about 250 F for about four or more hoursto remove essentially all water from the material. The dried material isfed into a heated cork screw extruder set at about 530 F to melt thematerial and ready it for injection into the mold 300. Before thematerial is injected into the mold 300, attachment inserts 44 may bepositioned in the mold. Alternative and/or additional elements, e.g.,framing and/or strengthening elements and related attachment inserts mayalso be placed in the mold 300 before injection. Exemplary elements aredescribed in co-pending U.S. patent application Ser. No. 10/958,079, thedisclosure of which is incorporated herein by reference in its entirety.A configuration of a window panel fabricated in such manner is indicatedgenerally in FIG. 8 by reference number 400. The window panel 400 mayinclude an embedded frame 404 fabricated, for example, of aluminumand/or a composite material, to be used in conjunction with or in lieuof inserts 44.

When the polymeric material has reached about 530 F, it is forced intoan accumulator (not shown) that contains a pressure piston. Forinjection of the material, the pressure piston is actuated and appliesbetween about 1500 and about 2000 psi pressure on a polymer shot that isforced into the closed mold 300. Once the material is injected, it maybe held at between about 1500 and about 2000 psi pressure for a dwelltime of approximately 20 minutes to allow for packing and cooling of thematerial in the mold 300. The mold may be held at about 350 F to allowfor rapid polymer injection without freezing and to allow for polymershrinkage that may take place during the cool-down packing cycle. Afterthe packing cycle, the mold 300 is opened and the window panel isremoved.

In one implementation, the window panel 20 may be installed relative toa structure such as the fuselage 12 in the following manner. Upper andlower edges 60 and 80 and one or more side edges 48 of the panel 20 arematched to an opening 32 in the structure 12 such that a curvature ofthe structure is made continuous by a curvature of the panel 20 over theopening 32. A plurality of fasteners 112 and/or 224 are installed into aplurality of panel attachment inserts 44 embedded alongside at least oneof the edges 60, 80 and/or 48 of the panel 20 to attach the panelrelative to the structure 12. It should be understood that although onetype of attachment insert (i.e., the insert 44) and two types offasteners (i.e., fasteners 112 and 224) are shown in the Figures anddescribed herein, various types, shapes and/or sizes of inserts and/orfasteners could be used to install window panels. For example, more thanone type of attachment insert could be embedded in a single panel,and/or a single type of fastener might be used to install a windowpanel.

Embodiments of the foregoing window panel make it possible to includelarger, more contoured windows in an aircraft or other structure thanwas previously possible. Polycarbonate, acrylic and/or polyurethanewindows of the present invention can be made to include impact-tolerant,ballistic-resistant and/or explosion-resistant properties. The foregoingwindow panel can be aerodynamically shaped for use in aircraft and othermoving structures. The window panel can also be coated, for example,with an electrochromic coating to provide window darkening.Injection-molding large panels enables the fabrication of a series ofwindows in a one-shot process that significantly reduces over-all laborand cost compared to fabricating individual windows.

The foregoing configurations can provide large, low-cost,aerodynamically shaped window panels that possess structural strengthand optical clarity throughout a high-curvature field of view. Theforegoing window panels also are lighter in weight than the combinationdouble-pane aircraft windows and the window-supporting structurescurrently in use. Weight can be reduced by as much as forty to sixtypercent when four to six windows are provided as a single panel asdescribed herein. Window panels configured in accordance with principlesof the present invention can be single-pane, do not require frames andcan provide an essentially continuous window along the length of anaircraft fuselage.

While various preferred embodiments have been described, those skilledin the art will recognize modifications or variations which might bemade without departing from the inventive concept. The examplesillustrate the invention and are not intended to limit it. Therefore,the description and claims should be interpreted liberally with onlysuch limitation as is necessary in view of the pertinent prior art.

1. A window panel adapted for installation relative to a mobile vehicle,the window panel comprising: a single piece of generally transparentinjection-molded material configured to span one or more openings in themobile vehicle, the material having an inner surface and an outersurface; and a plurality of panel attachment inserts for attaching thepanel relative to a frame component of the mobile vehicle, the insertseach embedded in the material during a molding process in which thewindow panel is formed such that each said attachment insert isnon-removable from the material once the material hardens to form thewindow panel, and each said attachment insert further being arrangedalongside at least one edge of the window panel without any portion ofthe attachment insert projecting from a peripheral edge of the material;each of the attachment inserts having a proximal end and a distal end,and where at least a portion of the proximal end is exposed from saidinner surface of the material and accessible after being embedded in thematerial, and each said distal end is covered by said outer surface ofthe material and inaccessible, and wherein each said proximal end isadapted to engage with an external fastener component for securing thewindow panel to the frame component; the window panel further comprisinga curvature configured to essentially continue a curvature of the mobilevehicle surrounding the one or more openings when the window panel isinstalled relative to the mobile vehicle.
 2. The window panel of claim1, wherein one of the attachment inserts comprises a metallic material.3. The window panel of claim 1, wherein the fastener is installedthrough the proximal end of the attachment insert without penetratingthe distal end.
 4. The window panel of claim 1, wherein theinjection-molded material is selected from the group consisting ofpolycarbonate, acrylic, and polyurethane.
 5. The window panel of claim1, wherein the frame component forms at least one of a longeron and ahoop frame of a fuselage of the mobile vehicle.
 6. The window panel ofclaim 1, wherein the injection-molded material comprises aballistic-resistant material.
 7. The window panel of claim 1, whereineach said attachment insert comprises: a dovetail shape when viewed incross section; and the attachment insert being embedded in the materialsuch that the proximal end is arranged adjacent said inside surface ofthe window panel and the distal end is arranged to face toward saidouter surface of the window panel.
 8. The window panel of claim 7,wherein the proximal end has a smaller dimension than the distal end. 9.The window panel of claim 1, wherein substantially an entire portion ofsaid first surface of the attachment insert adjacent the proximal end isexposed after the attachment insert is molded into the material.
 10. Anaircraft comprising: a fuselage defining one or more openings; a windowpanel adapted to be installed in at least one of the openings in thefuselage, the window panel including: a single piece of generallytransparent injection-molded material having an inside surface and anouter surface, and configured to span one or more of the openings in thefuselage; a plurality of panel attachment inserts for attaching thewindow panel relative to the fuselage, the panel attachment inserts eachhaving a single piece construction with a shape that enables each saidpanel attachment insert to be embedded in the material during a moldingprocess so as to be non-removable from the material, while stillenabling a first surface thereof to be exposed and accessible from theinside surface of the material, while a second surface thereof iscovered by the material and inaccessible from the outer surface of thematerial, wherein each attachment insert includes a proximal end and adistal end, and wherein said first surface is at said proximal end andsaid second surface is at said distal end, and each of the attachmentinserts further being arranged alongside at least one edge of the windowpanel, without any portion of the attachment insert projecting from aperipheral edge of the material; a plurality of fasteners adapted toengage the first surface of each said attachment insert after the windowpanel is positioned within the at least one of the openings, and to holdthe window panel to the fuselage; and the window panel further having acurvature configured to essentially continue a curvature of the fuselagesurrounding the one or more openings when the window panel is installedrelative to the fuselage.
 11. The aircraft of claim 10, wherein saidfirst surface is arranged substantially co-planar with said insidesurface of the material, and wherein each said fastener is installedthrough the first surface and the proximal end of the attachment insertwithout penetrating the distal end of the attachment insert.
 12. Theapparatus of claim 10, wherein the fuselage includes at least a portionof an aircraft fuselage skin.
 13. The window panel of claim 10, whereineach said attachment insert comprises: a dovetail shape when viewed incross section; and the attachment insert being embedded in the materialsuch that the proximal end is arranged adjacent said inside surface ofthe window panel and the distal end is arranged to face toward saidouter surface of the window panel.
 14. An aircraft comprising: afuselage defining one or more openings; and a window panel having aninside surface and an outside surface, the window panel being adapted tobe installed in at least one of the openings in the fuselage, the windowpanel including: a single piece of generally transparentinjection-molded material configured to span one or more of the openingsin the fuselage, the material having an inner surface and an outersurface; a plurality of panel attachment inserts for attaching thewindow panel relative to the fuselage, the panel attachment inserts eachhaving a dovetail shape when viewed in cross section with a proximal endand a distal end; each of the attachment inserts further being embeddedin the material during a molding process so as to be non-removable fromthe material, while still enabling a first surface adjacent the proximalend thereof to be exposed and accessible, and each of the attachmentinserts further being arranged alongside at least one edge of the windowpanel and positioned such that the first surface adjacent the proximalend is generally coplanar with the inside surface of the window panel,and further such that no portion of the attachment insert projects froma peripheral edge of the material, and further such that a secondsurface adjacent the distal end is covered by the outer surface andinaccessible; a plurality of fasteners adapted to engage the firstsurface of each said attachment insert after the window panel ispositioned within the at least one of the openings, and to hold thewindow panel to said fuselage; and the window panel further having acurvature configured to essentially continue a curvature of the fuselagesurrounding the one or more openings when the window panel is installedrelative to the fuselage.